The present invention relates to a pocket-size time domain reflectometer. More particularly, the present invention relates to a reflectometer for testing a cable to determine the impedance characteristics of the cable at any point along its length, where the reflectometer is small in size and provides a meter reading indicative of the impedance characteristic at a predetermined distance along the cable.
Reflectometers for testing cables are known. Conventionally, reflectometers generate a test signal which is transmitted to a cable that is to be tested. The cable then generates a reflection of the test signal and transmits the reflection back to the reflectometer. The reflectometer senses the reflection, and displays it on an oscilloscope. The display on the oscilloscope enables an operator to determine the impedance characteristics at any point of the cable that is being tested. Such reflectometers have disadvantages in that the use of an oscilloscope tends to make the reflectometer bulky and not well suited for being pocket-size. Such reflectometers generally contain complicated high speed circuitry for displaying the reflection of the test signal from the cable in real time. This type of reflectometer gives a total picture of the impedance characteristic along the entire cable length at a glance, however, it is expensive and relatively large in size.